Definition
Sinornis refers to an early bird genus from the Cretaceous period. It was a small, sparrow-sized bird that lived in what is now China. Unlike Archaeopteryx, Sinornis had features closer to modern birds. It had a shorter tail and an alula (a 'thumb' wing feather) for improved flight. Think of it as the next-gen version of early avian species. It's like upgrading from a biplane to a Cessna.